Function assert_update_works

backend/tests/git/topic.rs:705–719

(repo_1: RepoId, repo_2: RepoId, expected_parent_topics: &[&str])

    }

    fn assert_update_works(repo_1: RepoId, repo_2: RepoId, expected_parent_topics: &[&str]) {
        let result = upsert_topic(repo_1, repo_2, "Topic name").unwrap();
        assert!(result.repo_topic.is_some());
        assert!(result.saved);

        let parent_topics = result
            .repo_topic
            .unwrap()
            .parent_topics
            .iter()
            .map(|topic| topic.id.to_string())
            .collect::<Vec<String>>();

        assert_eq!(parent_topics, expected_parent_topics);
    }

    #[test]
    fn update_topic() {